Had a buddy who was obsessed with the ending. He spent a week rewriting it in his head, raging online. Finally saw some chats that made it click for him.
Your buddy rewriting the ending in his head is familiar, but that can just keep you stuck in your own idea. Looking at other people's views, like in those chats, often breaks you out of that loop. It makes sense that's what helped him get it.
Some endings just need to sit with you for a bit to make sense. It can feel really personal when a story doesn't wrap up how you wanted. Getting that moment where it finally clicks is the best feeling.